Spotter Ready user manual.

Getting Started

Spotter Ready calculates firing solutions and trajectory data from your rifle, load, optic, target, and environment. Good outputs require complete and accurate inputs.

1. Create or select a rifle profile.
2. Add the load: bullet, ballistic coefficient, muzzle velocity, zero range, sight height, and relevant twist data.
3. Choose optic settings and correction units.
4. Update environment from GPS weather, manual input, or a supported weather meter.
5. Open Firing Solution for a single target distance or Trajectory Table for a range card.

Profiles

Profiles group rifle, load, optic, and optional handloading details. Use one profile per rifle/load combination you want to preserve.

Rifle and load inputs

• Enter caliber, bullet, ballistic coefficient, muzzle velocity, zero range, sight height, and barrel twist.
• Use temperature-adjusted muzzle velocity when you have a verified velocity change per degree.
• Enable spin drift only when twist direction and twist rate are correct.

Optics and reticles

• Set MIL or MOA units to match your optic.
• Configure click values if you want click counts in the firing solution or trajectory table.
• Use reticle settings for visual holds and reticle card output.

Reloader mode

Reloader mode adds handloading fields such as powder, charge, primer, overall length, case brand, and notes. These details are stored with your profile and included in backups.

Environment

Environment affects drag and trajectory. Spotter Ready supports manual values, live weather, weather meters, and density altitude workflows.

• Use Update Environment to fetch temperature, pressure, humidity, altitude, and location for your current GPS position.
• Use supported weather meters for on-site atmospheric readings and wind data.
• Watch for stale environment warnings. Amber and red indicators mean conditions should be refreshed.
• If using density altitude, confirm whether the app is treating your meter value as density altitude rather than physical altitude.

GPS live weather uses the device GPS altitude for the environment. That avoids relying on distant weather station elevation.

Firing Solution

The Firing Solution screen is for a single target distance. It displays elevation and windage, plus optional click counts and voice readout.

Typical workflow

1. Select the active profile.
2. Confirm environment and wind.
3. Set target distance, shot angle, and wind direction.
4. Review elevation, windage, clicks, moving target lead, cant, spin drift, Coriolis, and Eotvos options as needed.
5. Use the reticle view for visual hold reference when configured.

Cant, angle, and Coriolis

You can enter cant manually, measure cant with the phone accelerometer, or use supported external sensors. Coriolis and Eotvos corrections are most meaningful at longer distances and require accurate bearing, latitude, and elevation angle.

Trajectory Table

The Trajectory Table creates a range card for the active profile. Configure the range interval, max distance, columns, units, wind speed, and click display in settings.

• Use independent wind hold columns to compare multiple wind values.
• Enable velocity, energy, time of flight, spin drift, and click columns when useful.
• Export or share the table for printed cards, notes, or offline reference.
• Use Reticle Card to view impacts in the scope reticle at selected ranges and wind conditions.

Voice Commands

Voice mode uses on-device speech recognition. It is designed for hands-free field adjustments, but it should be practiced before relying on it.

Activating voice mode

Tap the microphone on the Firing Solution screen. When voice mode is active, use short commands and wait for confirmation before issuing another command.

Common command types

• Set distance, wind speed, wind direction, and shot angle.
• Say repeat to hear the current solution again.
• Say update weather to fetch fresh conditions.
• Say help to hear recognized command examples.

Tools

Spotter Ready includes standalone tools for field cards, range estimation, profile validation, chronograph work, weather meters, and load development. Many tools can use the active profile as a starting point, but always confirm the displayed inputs before applying results back to a profile.

Reticle Manager

Reticle Manager lets you upload, calibrate, edit, delete, and assign reticle images. Add a reticle by entering the brand, reticle name, and angular unit, then upload an image.

• Use Set Center to drag the center marker to the optic center. Pinch to zoom when you need finer control.
• Use Set Scale to place the scale markers on two known reticle marks, then enter the angular distance between them.
• A calibrated reticle stores its center and pixels-per-unit value. Assign it in Optic settings before using Reticle View or Reticle Card.

Camera Range Estimator

The Camera Range Estimator is experimental. Photograph a target of known size and drag the two handles to mark that known dimension. The app uses the measured pixel span and camera focal information to estimate distance.

• Common target presets include deer shoulder, elk shoulder, human standing height, wild boar shoulder, IPSC target height, and custom sizes.
• If the photo has no focal length in EXIF, the estimate may be inaccurate. Use focal length calibration by aiming at a known-size target at a known distance.
• When the estimate is useful, add it directly to Target Card.

Target Card

Target Card builds a multi-target dope card with shared wind controls. Add targets by distance and optional label, then view each target with elevation and wind correction columns.

• Use the shared wind control to update the whole card when wind changes.
• Save cards with a description, load saved cards later, or delete saved cards you no longer need.
• Tap a target's firing-solution action to move that distance into the Firing Solution workflow.

Velocity Sensitivity to Temperature

This tool calculates muzzle velocity change per degree from chronograph readings taken at known temperatures. Enter at least two valid temperature and velocity readings; the app reports interval results and can update the current profile.

• Use readings from the same rifle, load, chronograph setup, and comparable firing conditions.
• Save the result only when the trend is based on reliable data rather than a single noisy session.

Chronograph

The Chronograph area contains device-specific import screens and shared chronograph data management.

• Athlon Rangecraft: scan, connect by Bluetooth, and sync completed sessions from the paired chronograph.
• Garmin Xero C1 Pro: export a completed session from Garmin ShotView as a FIT file, then import it into Spotter Ready.
• Chronograph Data: review all imported sessions and shot data, rename or delete sessions, export a session as CSV, apply muzzle velocity statistics to the selected profile, or create shot log entries.

Synced sessions show count, average velocity, standard deviation, extreme spread, minimum, and maximum velocity. When creating shot log entries, predicted elevation and windage are filled from the selected profile and current firing solution context where available.

Reticle Ranging

Reticle Ranging calculates target distance from a known target size and a measured reticle subtension in mils or MOA.

• Enter the target size and unit, then enter the reticle reading.
• Results are shown in yards and meters.
• For second focal plane reticles, enable SFP correction when you are not at the scope's calibrated magnification. Enter the current magnification and max magnification so the app can correct the reading.

Hit Probability

Hit Probability estimates the chance of hitting a circular or rectangular target at a given range using target size, stored group size, muzzle velocity standard deviation, and shot-condition confidence levels.

• Target options include circular diameter or rectangular width and height.
• Shot condition controls include shooter steadiness, wind variability, and range confidence, with presets such as benchrest, prone supported, standing, laser, LRF, mil-dot, and estimated range.
• The error budget combines group dispersion, aim error, wind estimate error, muzzle velocity variation, and range uncertainty by root-sum-of-squares.

The model assumes independent normal errors centered on the corrected firing solution. It does not model fatigue, extreme wind spikes, or systematic zero/profile errors.

Point Blank Range

Point Blank Range calculates the maximum range where the bullet remains inside a specified vital-zone radius. Inputs include drag function, BC, muzzle velocity, bullet weight, sight height, vital-zone radius, and atmosphere.

• The tool reports maximum point blank range, suggested zero range, muzzle energy, and terminal energy.
• Sight height must be smaller than the vital-zone radius for a valid calculation.

Group Size

Group Size converts a linear group measurement into MOA and MRAD. Use it to translate measured paper groups into the group-size value used by profile precision fields and Hit Probability.

• Enter group size and distance using the configured units.
• The result gives angular group size in both MOA and MRAD.

Shot Log Manager

Shot Log Manager reviews shot logs across profiles. Use it to filter, rename, delete, export, and analyze logged shots.

• Export shot log data to CSV for spreadsheet review.
• Use group-size calculation from logged impact data where appropriate.
• Use the main Shot Log screen for per-rifle summary data such as mean center, standard deviation, and extreme spread.

Sunrise / Sunset

Sunrise / Sunset calculates civil twilight and daylight information for a date and location.

• Enter year, month, day, latitude, longitude, time-zone offset, and daylight-saving setting.
• Use GPS to populate location when permission and signal are available.
• The tool reports sunrise, sunset, and day length, and handles polar cases where the sun is above or below the horizon all day.

Weather Meter

The Weather Meter area connects to supported Bluetooth weather meters and displays live readings. Supported screens include Kestrel Weather Meter and Tempest WEATHERmeter.

• Kestrel Weather Meter: scan for nearby Nielsen-Kellerman Kestrel 5700 series meters, connect, and view wind, temperature, humidity, pressure, altitude-related data, and speed of sound where available.
• Tempest WEATHERmeter: scan and connect to a Tempest WEATHERmeter for wind speed, wind direction, temperature, humidity, pressure, battery, and speed of sound. The wireless range setting can be switched between low range and high range.
• Weather-meter readings can be used as live field inputs, but confirm unit settings and whether your workflow uses physical altitude or density altitude.

BC from Velocity

BC from Velocity derives ballistic coefficient from near and far chronograph velocity readings. Inputs include drag function, near velocity, far velocity, distance between readings, atmosphere, bullet weight, and related ballistic parameters.

• The near velocity must be greater than the far velocity.
• Use chronographs that are well aligned and far enough apart for the velocity loss to be meaningful.

BC from Time of Flight

BC from Time of Flight derives ballistic coefficient from measured time of flight. Inputs include drag function, muzzle velocity, distance, time of flight, atmosphere, and bullet data.

• The entered time of flight must be physically possible for the entered velocity and distance.
• This tool is only as good as the timing and distance measurements used to feed it.

Maximum Distance

Maximum Distance estimates the maximum range a bullet can travel and its absolute maximum height. Enter ballistic inputs and firing elevation angle.

• Results include terminal range, maximum height, terminal angle, terminal velocity, terminal energy, absolute straight-up maximum height, and time up.
• This is a physics reference tool, not a substitute for safe backstop and range procedures.

Trajectory Truing

Trajectory Truing fits muzzle velocity or ballistic coefficient from two or three confirmed impacts fired with the current firing solution. It reduces residual error across the selected distances.

• Choose Fit MV or Fit BC.
• Confirm ballistic parameters, environment, zero range, sight height, and drag model before calculating.
• Add observed impacts manually or import shot log entries with vertical impact data from the active profile.
• For each observation, enter distance and impact offset above or below point of aim.
• Results include corrected muzzle velocity or BC, adjustment, BC scale factor, RMS error before and after fit, and per-observation residuals.
• Save the corrected muzzle velocity to the active profile or corrected BC to the active load only after validating the observations.

Gyroscopic Stability

Gyroscopic Stability calculates Miller stability factor, Sg, for the active bullet and barrel twist. Use it to check whether a bullet is likely to be adequately stabilized by the rifle.

• Inputs are based on bullet dimensions, bullet weight, muzzle velocity, atmospheric conditions, and barrel twist.
• Low stability can indicate poor bullet choice, insufficient twist, or conditions that need separate validation.

Bullet Database

Bullet Database browses and filters the built-in bullet library. Filter by manufacturer, caliber, BC, and other bullet fields, then use the data as a reference when building loads.

• Clear filters to return to the full library.
• Export CSV when you want to review bullet records outside the app.
• Confirm manufacturer BC standard and drag model before using a bullet in a live profile.

Trajectory Graphs

Trajectory Graphs plots trajectory outputs against distance. Y-axis choices include drop, windage, velocity, and energy, with linear, MOA, and MRAD options where applicable.

• Compare multiple values for altitude, muzzle velocity, wind speed, temperature, zero range, or profile.
• Select one or more profiles, set max range, and tap Plot.
• Export or share the resulting graph when you need a visual comparison outside the app.

Shot Log

Shot Log records actual shots for later analysis. Use it to compare predicted and actual corrections, impact offsets, environment, and profile data.

• Log shot distance, predicted elevation and windage, actual correction, impact offset, and notes.
• Use per-rifle summaries to identify trends.
• Import compatible chronograph sessions and create shot log entries from synced shots.

Backup and Restore

Spotter Ready uses an open JSON database format for backup and restore. You own the exported file and choose where to store it.

1. Open the backup or data management area in the app.
2. Export a JSON backup before changing phones, reinstalling, or testing large profile changes.
3. Store the file somewhere you control, such as encrypted cloud storage or an offline archive.
4. Use Restore only with a file you trust and intend to import.

Safety Notes

Spotter Ready is a calculator and field aid. It does not replace safe firearm handling, verified range procedures, local laws, range rules, qualified instruction, or real-world confirmation of your rifle and load.

• Confirm zero and muzzle velocity with live fire.
• Never use an unverified profile for critical shots.
• Understand your backstop, target, environmental conditions, and ethical limits.
• Validate predictions at distance before relying on them in the field.